Tailings Management

Responsible management of tailings is an important focus of MAC and its members. Tailings are an unavoidable by-product of mining, consisting of the processed rock or soil left over from the separation of the commodities of value from the rock or soil within which they occur. If not managed responsibly, tailings can pose potential risks to human health and safety, the environment, infrastructure, and to mining companies themselves. Responsible tailings management is, therefore, essential to minimizing and mitigating these risks.

In November 2017, MAC released a revised edition of its internationally-recognizedA Guide to the Management of Tailings Facilities[1][1](the Tailings Guide). The third edition of the Tailings Guide is another step in the continual improvement process for tailings management, moving towards the goal of minimizing harm: zero catastrophic failures of tailings facilities, and no significant adverse effects on the environment and human health. It contains new technical components, including those critical to the physical and chemical stability of tailings facilities. It also strengthens key management components throughout the tailings facility’s life cycle, such as change management, critical controls for risk management, and performance evaluation.

Tailings management is also a core focus of MAC’s sustainability standard, the Towards Sustainable Mining[3]® (TSM®) initiative, which was launched in 2004. Performance indicators for tailings management are described in the TSM Tailings Management Protocol[4]. The Protocol is supported by the Tailings Guide and the OMS Guide, all of which are designed to help ensure the safe and environmentally responsible management of tailings throughout the full life cycle of a facility.

Canadian tailings management guidance is recognized as globally leading. For example, the BC Government-appointed Independent Expert Panel that examined the 2014 tailings incident at the Mount Polley Mine in British Columbia recommendedin its report[5] that any mining operation proposing to operate a tailings facility in BC should either be required to be a member of MAC—ensuring adherence to TSM—or be obliged to commit to an equivalent program with an audit function.

A 2016 report by Golder Associates[6], commissioned by the International Council on Mining and Metals following the tailings failure at the Samarco mine in Brazil, noted that the Canadian guidelines produced by MAC and the Canadian Dam Association, taken together, were the most comprehensive of the national frameworks examined, while also noting potential improvements.

Notwithstanding such recognition of Canadian guidance, MAC proactively reviewed its tailings management components to ensure they continued to contain leading practices. Following the tailings incident at Mount Polley, MAC struck an Independent Task Force to undertake an external review, which ultimately made 29 recommendations[7] to strengthen MAC’s tailings management guidance and requirements under TSM—all of which are being systematically incorporated. A parallel internal review, spearheaded by tailings experts within MAC’s membership, was also conducted. This identified further opportunities, including those identified in the 2016 Golder report, to strengthen MAC’s tailings management components and incorporate proven and emerging best practices. Since then, MAC has updated the TSM Tailings Management Protocol and the Tailings Guide. Revisions to the OMS Guide are currently in progress.